Image forming apparatus

Abstract

To enable the quality of an image as a whole to be secured by resuming image formation and forming a remaining portion even when the quality of image formation temporarily deteriorates in suspension of the operation of image formation.SOLUTION: A conveyance mechanism 2 conveys a sheet P from a feeding tray 1 along a prescribed conveyance direction. A head 5 forms an image on the sheet P conveyed by the conveyance mechanism 2. A control unit 9 causes the conveyance mechanism 2 and the head 5 to execute the normal printing operation of forming an image shown by image data received from the outside on the sheet P. When the normal printing operation is suspended, the control unit 9 causes the conveyance mechanism 2 and the head 5 to execute an additional printing operation of forming an image shown by the image data in a reverse direction to that of the normal printing operation in a region of the sheet P different from a region where the image is formed in the normal printing operation before suspension, until timing indicated by the user input received by a touch panel display 95.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an image forming apparatus that forms an image on a sheet-like medium.

Background Art

[0002] In an image forming apparatus that forms an image on a sheet-like medium, the operation of forming an image may be interrupted for various reasons. For example, in the printer described in Patent Document 1, when the remaining amount of ink used for forming an image decreases, the operation of forming an image is temporarily continued, and then when the timing for a good separation is reached in the subsequent operation of forming an image, the image formation is interrupted. Then, the ink container with the decreased remaining amount of ink is replaced. After that, the image formation is restarted.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When the formation of an image is interrupted, depending on the situation of the interruption, the quality of the image formation immediately before the interruption may deteriorate. For example, in the case where ink is used for image formation as in Patent Document 1, when the operation of image formation is continued despite the decrease in the remaining amount of the ink, there is a possibility that a sufficient amount of ink for ensuring the quality of the image is not used for image formation. In this case, even if the formation of the image is restarted after the quality of the image formation is restored by replacing the ink tank and the remaining part is formed on the sheet-like medium, the quality of the image formation remains partially deteriorated.

[0005] An object of the present invention is to provide an image forming apparatus that can ensure the quality of an image as a whole by restarting the image formation and forming the remaining part even if the quality of the image formation temporarily deteriorates during the interruption of the operation of image formation. [Means for solving the problem]

[0006] The image forming apparatus of the present invention comprises a media storage unit for storing a sheet-like medium, a media transport unit for transporting the sheet-like medium from the media storage unit along a predetermined transport direction, an image forming unit for forming an image on the sheet-like medium transported by the media transport unit, a user input unit for receiving user input, and a control unit. The control unit performs a first control that causes the image forming unit and the media transport unit to perform a first operation in which an image indicated by image data received from an external source is formed on the sheet-like medium from one end to the other in the vertical direction of the image, corresponding to the predetermined transport direction. If the first operation is interrupted, the control unit performs a second control that causes the image forming unit and the media transport unit to perform a second operation in which an image indicated by the image data is formed in a region of the sheet-like medium different from the region in which the image was formed in the first operation before the interruption, from the other end to the one end, until a timing indicated by user input received by the user input unit. [Effects of the Invention]

[0007] According to the image forming apparatus of the present invention, if the first operation of forming an image on a sheet-like medium from one end to the other is interrupted, a second operation is performed to form an image on the sheet-like medium in the opposite direction to the first operation, from the other end to the first end. If there is a possibility that the quality of image formation has deteriorated immediately before the interruption of the first operation, measures are taken to restore the quality of image formation between the interruption of the first operation and the start of the second operation. For example, if the interruption of the first operation is due to insufficient ink, the ink container is replaced. After that, a sheet-like medium with the entire image formed can be obtained by appropriately cutting and pasting the sheet-like medium to connect the image formed in the first operation and the image formed in the second operation. Even if the quality of the image formed immediately before the interruption of the first operation has deteriorated, the overall image quality can be ensured by separating the deteriorated portion from the image formed in the first operation and connecting it with the image formed in the second operation.

[0008] In addition, in the second operation of the present invention, the user can confirm the image being formed on the sheet-like medium in the reverse direction and terminate the second operation at the timing deemed necessary by user input. Therefore, the second operation can form an image on the sheet-like medium within an appropriate range that can be joined together with the image formed in the first operation. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic side view showing the internal structure of a printer according to one embodiment of the present invention. [Figure 2] This block diagram shows the electrical configuration of the printer shown in Figure 1. [Figure 3] Figure 1 shows an example of an image formed on paper by a normal printing operation performed by the printer shown. [Figure 4] This is a surface view of the paper, showing an example of the image formation status immediately before the interruption of the normal printing operation for the image in Figure 3. [Figure 5] As shown in Figure 4, this is a surface view of the paper illustrating the process of image formation through additional printing operations after a normal printing operation has been interrupted. [Figure 6] This is a screen showing the formation status of the image displayed on the touch panel display in Figure 1. [Figure 7] Figure 1 is a flowchart showing the flow of the image formation process by the printer. [Modes for carrying out the invention]

[0010] [First Embodiment] A printer 100 (corresponding to the "image forming apparatus" of the present invention) according to the first embodiment, which is a preferred embodiment of the present invention, will be described below with reference to Figures 1 to 7. The vertical, horizontal, and front-to-back directions shown in Figure 1 will be referred to as the vertical, horizontal, and front-to-back directions of the printer 100.

[0011] As shown in Figures 1 and 2, the printer 100 mainly comprises a housing 100a, a feed tray 1, a transport mechanism 2, a cutter 3, a carriage 4, a head 5, a moving mechanism 6, a paper output tray 7, and a control unit 9.

[0012] The feeding tray 1 (corresponding to the "media storage section" of the present invention) is located below the head 5 within the housing 100a. The feeding tray 1 can be inserted into and removed from the housing 100a in the front-rear direction through an opening 10p formed in the front wall of the housing 100a.

[0013] The feeding tray 1 is capable of accommodating rolls R and cut sheets Kp. The feeding tray 1 may be capable of accommodating both rolls R and cut sheets Kp simultaneously, or it may be capable of selectively accommodating either rolls R or cut sheets Kp. The feeding tray 1 has a roll support section 11 for supporting rolls R and a mounting surface 12 on which cut sheets Kp are placed.

[0014] The roll body R is a long sheet of paper wound in a roll around the outer circumference of a cylindrical core member Rc. The cut paper Kp is a sheet of paper shorter than the long sheet of paper that makes up the roll body R, and is a standard size such as A4 or B5. The largest size of cut paper Kp that can be used with the printer 100 of this embodiment is A4 size paper. Multiple sheets of cut paper Kp are placed on the mounting surface 12 in a stacked state.

[0015] The transport mechanism 2 transports the paper P from the feed tray 1 through the head 5 to the output tray 7 (the path along the thick black line representing the paper P in Figure 1). Hereinafter, the terms "upstream" and "downstream" refer to the upstream and downstream directions of the transport of the paper P along the transport path by the transport mechanism 2, respectively. The transport mechanism 2 (corresponding to the "media transport section" of the present invention) has a feed roller 21, an intermediate roller pair 22, a transport roller pair 23, an output roller pair 24, and a guide member 25. These rollers and roller pairs are arranged in the order of feed roller 21, intermediate roller pair 22, transport roller pair 23, and output roller pair 24 along the transport path from upstream to downstream.

[0016] The feeding roller 21 feeds the roll paper Rp unwound from the roll body R supported by the roll body support portion 11 or the cut paper Kp placed on the placement surface 12 from the feeding tray 1. In the following description, when the roll paper Rp and the cut paper Kp are not distinguished, they are referred to as "paper P".

[0017] The feeding roller 21 rotates by the drive of a feeding motor 21a (see FIG. 2). When the feeding motor 21a is driven under the control of the control unit 9, the feeding roller 21 rotates, and a conveying force in the direction from the front to the rear is applied to the paper P in contact with the feeding roller 21. Thereby, the paper P is sent out from the feeding tray 1. Note that the rear wall 15 provided at the rear end of the feeding tray 1 is inclined such that the upper end portion is located behind the lower end portion. Therefore, the paper P sent out from the feeding tray 1 goes obliquely upward.

[0018] The intermediate roller pair 22 is composed of a driving roller that rotates by the drive of an intermediate motor 22a (see FIG. 2) and a driven roller that rotates along with the driving roller. When the intermediate motor 22a is driven under the control of the control unit 9, the intermediate roller pair 22 rotates while sandwiching the paper P and conveys the paper P. The intermediate roller pair 22 is located above the rear end of the feeding tray 1. The intermediate roller pair 22 sandwiches and conveys upward the paper P sent out from the feeding tray 1 by the feeding roller 21 and going obliquely upward. The guide member 25 is located above the intermediate roller pair 22. The guide member 25 guides the paper P conveyed upward by the intermediate roller pair 22 forward.

[0019] The conveying roller pair 23 is composed of a driving roller that rotates by the drive of a conveying motor 23a (see FIG. 2) and a driven roller that rotates along with the driving roller. The paper discharge roller pair 24 is composed of a driving roller that rotates by the drive of a paper discharge motor 24a (see FIG. 2) and a driven roller that rotates along with the driving roller.

[0020] When the conveyance motor 23a and the paper discharge motor 24a are driven under the control of the control unit 9, the pair of conveyance rollers 23 and the pair of paper discharge rollers 24 rotate while sandwiching the sheet P, and convey the sheet P forward in the conveyance direction. The pair of conveyance rollers 23 is located behind the head 5, and the pair of paper discharge rollers 24 is located in front of the head 5. The pair of conveyance rollers 23 further conveys the sheet P guided forward by the guide member 25 forward toward the pair of paper discharge rollers 24. The pair of paper discharge rollers 24 further conveys the sheet P conveyed forward by the pair of conveyance rollers 23 forward while sandwiching it, and discharges it to the paper discharge tray 7.

[0021] Near the conveyance path of the sheet P, sheet sensors 96 and 97 for detecting the presence of the sheet P on the conveyance path are installed. The sheet sensor 96 is disposed slightly below the pair of intermediate rollers 22, and the sheet sensor 97 is disposed slightly in front of the pair of conveyance rollers 23. The control unit 9 can detect whether a jam or paper clogging in which the sheet P remains on the conveyance path has occurred based on the detection results of the sheet sensors 96 and 97.

[0022] The cutter 3 is disposed at a position upstream of the pair of intermediate rollers 22 in the conveyance path and between the rear end portion on the rear side of the supply tray 1 and the pair of intermediate rollers 22. The cutter 3 includes, for example, a rotary blade and a driven blade in the shape of a disc. The cutter 3 rotates the rotary blade by driving a cutting motor 3a (see FIG. 2) and reciprocates in the left-right direction. The roll paper Rp unwound and conveyed from the roll body R is cut in the width direction of the roll paper Rp by the cutter 3 when the cutting motor 3a is driven under the control of the control unit 9. As a result, a rear end is formed on the roll paper Rp, and it is discharged to the paper discharge tray 7 as individual sheets.

[0023] The head 5 (corresponding to the "image forming unit" of the present invention) includes a plurality of nozzles formed on the lower surface and a driver IC 52 (see FIG. 2). When the driver IC 52 is driven under the control of the control unit 9, ink is ejected from the nozzles, and the ink adheres to the sheet P to form dots. The head 5 is mounted on the carriage 4.

[0024] The moving mechanism 6 includes two guide rails 61 and 62 and a carriage motor 63 (see Figure 2). The two guide rails 61 and 62 are spaced apart from each other in the front-rear direction and each extends in the left-right direction. The carriage 4 is positioned to straddle the two guide rails 61 and 62. The carriage 4 is connected to the carriage motor 63 via a belt (not shown) or the like. When the carriage motor 63 is driven by the control unit 9, the carriage 4 moves along the guide rails 61 and 62 in the scanning direction (left-right direction).

[0025] As the print head 5 moves back and forth in the scanning direction with the movement of the carriage 4, ink is ejected, sequentially forming dots along the scanning direction. These rows of dots along the scanning direction are sequentially formed as the paper P is transported by the transport mechanism 2. In the image-forming region on the paper P, dots are arranged in both the scanning and transport directions, and an image consisting of this arrangement of dots appears. The image-forming region is a rectangular area corresponding to the size of the image.

[0026] The output tray 7 is located in front of the head 5 and above the feed tray 1 within the housing 100a. The output tray 7 can be inserted into and removed from the housing 100a in the front-to-back direction through an opening 100q formed in the front wall of the housing 100a. Paper P on which an image has been recorded by the head 5 is received by the output tray 7.

[0027] A cartridge mounting section 8 is installed inside the housing 100a. Four ink cartridges, each storing black, yellow, cyan, and magenta ink, can be detachably installed in the cartridge mounting section 8. Ink is supplied to the print head 5 from the ink cartridges installed in the cartridge mounting section 8 via tubes or the like. The cartridge mounting section 8 is equipped with an ink level sensor 98 that detects the remaining amount of ink in each of the four ink cartridges. The control unit 9 can obtain the remaining amount of ink for each of the four ink cartridges based on the detection results of the ink level sensor 98.

[0028] A touch panel display 95 (corresponding to the "display" and "user input section" of the present invention) is installed on the front exterior of the housing 100a. The touch panel display 95 displays characters, images, etc., on the screen under the control of the control unit 9. The touch panel display 95 also detects the contact position when a finger or the like touches the screen and transmits the detection result to the control unit 9.

[0029] The control unit 9 controls the entire printer 100. As shown in Figure 2, the control unit 9 is electrically connected to the feed motor 21a, intermediate motor 22a, transport motor 23a, paper ejection motor 24a, cutting motor 3a, driver IC 52, carriage motor 63, touch panel display 95, paper sensors 96 and 97, and paper level sensor 98.

[0030] As shown in Figure 2, the control unit 9 includes a CPU (Central Processing Unit) 91, ROM (Read Only Memory) 92, RAM (Random Access Memory) 93, and ASIC (Application Specific Integrated Circuit) 94. The ROM 92 stores programs executed by the CPU 91 and ASIC 94. The RAM 93 temporarily stores data necessary for program execution. This data includes image data transmitted from external devices such as PCs or read from recording media.

[0031] Furthermore, the control unit 9 may perform various processing using only the CPU 91, or only the ASIC 94, or the CPU 91 and ASIC 94 may cooperate in performing various processing. Also, the control unit 9 may be performed by a single CPU 91 alone, or by multiple CPUs 91 sharing the processing. Furthermore, the control unit 9 may be performed by a single ASIC 94 alone, or by multiple ASICs 94 sharing the processing.

[0032] The control unit 9 performs normal printing control (corresponding to the "first control" of the present invention) to cause the transport mechanism 2, cutter 3, and head 5 to perform the following normal printing operation (corresponding to the "first operation" of the present invention). In the normal printing operation, the control unit 9 repeatedly alternately performs the following processes based on the image data stored in the RAM 93: transporting the paper P along the transport path by the transport mechanism 2 at predetermined distances, and moving the carriage 4 back and forth in the scanning direction by the movement mechanism 6 while ejecting ink from multiple nozzles of the head 5 onto the paper P.

[0033] When the paper P is roll paper Rp, the roll paper Rp receives ink ejected from the head 5 while being transported by the transport mechanism 2. The roll paper Rp is cut to the desired length by the operation of the cutter 3 according to the control of the control unit 9. The roll paper Rp cut by the cutter 3 becomes individual sheets of paper with the desired length and is discharged into the output tray 7. Figure 3 is an example of an image G formed on roll paper Rp by a normal printing operation. The image G is elongated in the longitudinal direction along the transport direction of roll paper Rp by the transport mechanism 2. The formation of the image G on roll paper Rp starts from one end G1 in the longitudinal direction and is formed toward the other end G2 in the longitudinal direction along the printing direction A1 parallel to the transport direction.

[0034] If the paper P is a cut sheet Kp, the cut sheet Kp is transported by the transport mechanism 2 and receives ink ejected from the head 5. As a result, the cut sheet Kp becomes a paper with an image recorded on it and is discharged into the output tray 7.

[0035] Based on the detection results of the paper sensors 96 and 97 and the ink level sensor 98, the control unit 9 interrupts the normal printing operation if any cause occurs that prevents the normal printing operation from continuing, such as insufficient ink, a jam, or a paper jam. Other causes of interrupting the normal printing operation include a power outage during operation or the power plug being unplugged from the outlet.

[0036] Figure 4 shows an example of the image G formation status on the roll paper Rp immediately before the interruption of a normal printing operation for image G. As shown in Figure 4, the image G is interrupted midway from one end G1 to the other end G2. Depending on the cause of the interruption of the normal printing operation, the quality of the portion of the image G on the roll paper Rp that was formed immediately before the interruption (the shaded area in Figure 4) may be degraded. For example, if the cause of the interruption is insufficient ink, it is possible that not enough ink was used in the image formation immediately before the interruption to meet the required image formation quality. When a normal printing operation is interrupted due to insufficient ink, the user replaces the ink cartridge with a new one. This removes the cause of the degradation in image formation quality. Therefore, it is conceivable to resume the normal printing operation afterward. However, even if the remaining portion is formed on the paper P after resuming the normal printing operation, the image formation quality in the portion immediately before the interruption will remain degraded.

[0037] Therefore, when the normal printing operation is interrupted, the control unit 9 executes additional printing control (corresponding to the "second control" of the present invention) which causes the transport mechanism 2, cutter 3, and head 5 to perform additional printing operations (corresponding to the "second operation" of the present invention).

[0038] The additional printing control is as follows: If the paper P corresponds to a roll of paper Rp, the additional printing operation is started on the next roll of paper Rp that is transported after the roll of paper Rp that interrupted the normal printing operation has been cut. If the paper P corresponds to a cut sheet of paper Kp, the additional printing operation is started on the next cut sheet of paper Kp that is transported after the cut sheet of paper Kp that interrupted the normal printing operation has been ejected. In the additional printing operation, the control unit 9 repeatedly alternates between transporting the paper P along the transport path by the transport mechanism 2 at predetermined distances based on the image data stored in the RAM 93, and reciprocating the carriage 4 in the scanning direction using the movement mechanism 6 while ejecting ink from multiple nozzles of the head 5 onto the paper P. In this operation, the control unit 9 controls the transport mechanism 2 so that the speed at which the paper P is transported is less than the speed of the normal printing operation. The control unit 9 then forms an image on the paper P in the opposite direction to the normal printing operation, starting from the edge of the image opposite to the normal printing operation. Figure 5 shows the situation in which an image is formed by the additional printing operation after the normal printing operation has been interrupted, as shown in Figure 4. As shown in Figure 5, the image formation begins at the opposite end G2 from the end G1, which is the starting end of the normal printing operation, and the image G is formed along the printing direction A2, which is opposite to the printing direction A1 of the normal printing operation.

[0039] Furthermore, the control unit 9 causes the touch panel display 95 to display the area of ​​the image G already formed on the paper P while continuously performing additional printing operations on the transport mechanism 2, etc. Figures 6(a) and 6(b) are examples of such displays. Both displays in Figures 6(a) and 6(b) include a portion of the image G and the "Print Complete" button image B. When the user's finger or the like touches the display area of ​​the button image B on the touch panel display 95, the control unit 9 determines that the button image B has been operated. The image G is shaded to represent the printed area and the unprinted area. The content of this display is updated according to the progress of image formation by the additional printing operation. For example, Figure 6(b) shows a situation where image formation has progressed further than in Figure 6(a). The user checks the display on the touch panel display 95, determines the timing to complete the additional printing operation, and touches the display area of ​​the button image B on the touch panel display 95 with their finger or the like. The timing for completing the additional printing operation is any time after the printed area exceeds the position where the paper P is joined in the subsequent operation (for example, the joining position in Figure 5). The control unit 9 continues the additional printing operation to the transport mechanism 2, etc., until the button image B is operated. The control unit 9 then completes the additional printing operation to the transport mechanism 2, etc., when the button image B is operated. It is preferable that the timing of the operation of the button image B and the timing of the completion of the additional printing operation coincide as much as possible, but a slight discrepancy may occur during processing.

[0040] With the above additional printing control, a continuation of the image corresponding to the remaining portion of the image interrupted by the interruption of the normal printing operation is formed on the paper P. If the paper P corresponds to a roll of paper Rp, the roll of paper Rp with the continuation image formed on it is cut by the cutter 3 and then discharged into the output tray 7. If the paper P corresponds to a cut sheet of paper Kp, the cut sheet of paper Kp with the continuation image formed on it is discharged into the output tray 7.

[0041] The user then obtains a sheet of paper P by appropriately cutting and pasting together the portion of the image formed by the normal printing operation and the portion of the image formed by the additional printing operation. For example, during this pasting process, the sheet of paper P is cut at a position where the portion of the image formed by the normal printing operation with reduced quality is precisely separated (for example, the pasting position in Figure 4). The sheet of paper P is also cut at a position corresponding to that cut position (for example, the pasting position in Figure 5) so that the image formed by the additional printing operation is cut. The cut sheets of paper P are then joined together at their respective cut positions using cellophane tape or the like. As a result, the entire image (see Figure 3) appears seamlessly on the pasted sheet of paper P. Alternatively, the sheet of paper P may be cut at a position outside at least one of the pasting positions in Figures 4 and 5, and the portions outside the resulting pasting positions may be glued together using adhesive as a gluing surface.

[0042] The following describes a specific example of the sequence of normal print control and additional print control performed by the control unit 9, referring to the flowchart in Figure 7. The flowchart in Figure 7 is applied as an example when roll paper Rp is used. First, the control unit 9 checks whether the remaining amount of ink in each of the four ink cartridges is sufficient to complete a normal print operation without replacing the cartridges, based on the detection result of the remaining amount sensor 98 and the image data stored in RAM 94 (S1). If it is determined that a normal print operation can be completed without replacing the cartridges (S2, Yes), the control unit 9 performs a normal print operation (S16) and terminates the series of controls.

[0043] If the control unit 9 determines that the normal printing operation cannot be completed to the end without replacing the cartridge (S2, No), it displays a screen on the touch panel display 95 allowing the user to choose whether or not to cancel the printing, and waits for user input (S3). If the control unit 9 determines in S3 that the user has selected to cancel the printing based on the operation of the touch panel display 95 (S4, Yes), it performs the processing for canceling the printing (S17) and then terminates the series of controls.

[0044] If the control unit 9 determines in S3 that the user has selected to continue printing based on the operation of the touch panel display 95 (S4, No), it displays a screen on the touch panel display 95 that allows the user to choose whether to replace the ink cartridge or continue printing, and waits for user input (S5). If the control unit 9 determines in S5 that the user has selected to replace the ink cartridge based on the operation of the touch panel display 95 (S6, Yes), it waits until the user has completed the ink cartridge replacement process (S18) and then returns to the process of S1.

[0045] If the control unit 9 determines in S5 that the user has selected to print as is based on the operation of the touch panel display 95 (S6, No), the control unit 9 displays a screen on the touch panel display 95 asking the user whether or not to agree to the processing required when the ink runs out, and waits for user input (S7). This screen includes a message such as, "If the ink runs out in the middle of printing, you will need to replace the ink cartridge and then print the remaining part to join the pages together. Is this alright?" and images of "YES" and "No" buttons to select whether or not to agree.

[0046] If the control unit 9 determines in S7 that the user has chosen not to agree based on the operation of the touch panel display 95 (S8, No), it performs the process to cancel printing (S19) and then terminates the series of controls. If the control unit 9 determines in S8 that the user has chosen to agree based on the operation of the touch panel display 95 (S8, Yes), it starts normal printing control (S9). If the normal printing operation is completed without interruption until the end (until the roll paper Rp with the image formed and cut is ejected into the output tray 7) (S10), the control unit 9 displays a screen on the touch panel display 95 prompting the user to select whether or not there is a problem with the quality of the image formed on the ejected roll paper Rp, and waits for user input (S11). If the control unit 9 determines in S11 that the user has chosen that there is no problem based on the operation of the touch panel display 95 (S12, Yes), it terminates the series of controls.

[0047] If the control unit 9 determines in S11 that the user has selected a problem based on the operation of the touch panel display 95 (S12, No), the control unit 9 executes additional printing control (S13). Next, the control unit causes the roll paper Rp on which the image has been formed by the additional printing operation to be cut by the cutter 3 and discharged by the transport mechanism 2 into the output tray 7 (S14). Then, the control unit 9 completes the series of processes.

[0048] Between S9 and S10, if the control unit 9 determines that the ink has run out based on the detection result of the ink level sensor 98, it generates an interrupt process that interrupts the normal printing process (S20). As a result, the control unit 9 causes the roll paper Rp to be cut by the cutter 3 and discharged into the output tray 7 by the transport mechanism 2 (S21). The control unit 9 then waits until the user has completed the ink cartridge replacement process (S22) before executing the additional printing control and subsequent processing in S13.

[0049] According to the embodiment described above, if the normal printing operation is interrupted, an additional printing operation is performed to form an image on the paper P in the opposite direction to the normal printing operation. If there is a risk that the image formation quality has deteriorated immediately before the interruption of the normal printing operation, measures to restore the image formation quality (for example, replacing the ink cartridge) are taken between the interruption of the normal printing operation and the start of the additional printing operation. After that, the paper P can be cut and pasted as appropriate to join the image formed in the normal printing operation and the image formed in the additional printing operation, thereby obtaining a paper P with the entire image formed. Even if the image quality has deteriorated immediately before the interruption of the normal printing operation, the overall image quality is ensured by separating the deteriorated portion from the image formed in the normal printing operation and joining it with the image formed in the additional printing operation.

[0050] In addition, in the additional printing operation of the present invention, the user can check the image being formed on the paper P in the reverse direction on the touch panel display 95 and terminate the additional printing operation at the timing deemed necessary by user input. Therefore, the additional printing operation makes it possible to form an image on the paper P within an appropriate range that can be joined together with the image formed in the normal printing operation.

[0051] Furthermore, during additional printing operations, the paper P is transported slowly, making it easier for the user to determine when to complete the additional printing operation. In addition, the user can determine when to complete the additional printing operation by viewing the continuously formed image through the sequentially updated display on the touch panel display 95.

[0052] [Second Embodiment] The following describes a second embodiment according to another embodiment of the present invention. The main difference between this embodiment and the first embodiment lies in the content of the additional print control; other configurations are common to both the first and second embodiments. Therefore, the following description will mainly focus on the differences from the first embodiment, and the same reference numerals will be used for components common to both embodiments, with their descriptions omitted as appropriate.

[0053] In the first embodiment, the additional printing control continuously performs the additional printing operation on the transport mechanism 2, etc., while displaying the range of the image G already formed on the paper P on the touch panel display 95. In contrast, the additional printing control in the second embodiment intermittently performs the additional printing operation on the transport mechanism 2, etc. Specifically, the process of transporting the paper P along the transport path by the transport mechanism 2 by a predetermined distance, and the process of moving the carriage 4 in the scanning direction by the movement mechanism 6 while ejecting ink from multiple nozzles of the head 5 onto the paper P are performed once or multiple times, and these operations are stopped alternately and repeatedly. The touch panel display 95 displays the range of the image G already formed on the paper P (see Figure 6). During the period when the operation is stopped, a screen is displayed on the touch panel display 95 allowing the user to select whether or not to complete the additional printing operation, and the system waits for user input. When it is determined that the user has selected to complete the additional printing operation based on the operation of the touch panel display 95, the additional printing control is terminated. On the other hand, if the touch panel display 95 determines that the user has selected to continue printing, the intermittent additional printing operation continues. According to this embodiment, the user can carefully determine the timing to complete the additional printing operation during the period when image formation is temporarily stopped.

[0054] [Third Embodiment] The following describes a third embodiment according to yet another embodiment of the present invention. The main difference between this embodiment and the first and second embodiments lies in the content of the additional print control; other configurations are common to the first and second embodiments and the third embodiment. Therefore, the following will mainly describe the differences from the first and second embodiments, and the same reference numerals will be used for components common to the first and second embodiments, with their descriptions omitted as appropriate.

[0055] In the additional print control according to the third embodiment, a screen for selecting print completion is displayed on the touch panel display 95. However, unlike the first and second embodiments, the touch panel display 95 does not display the range of the image G already formed on the paper P. Instead, the user determines the timing to complete the additional print operation by checking the image formed on the ejected paper P. When the user determines that this timing has been reached, they operate the touch panel display 95 to complete the additional print operation.

[0056] <Variation> Although embodiments of the present invention have been described above with reference to the drawings, it should be understood that the specific configurations are not limited to these embodiments. The scope of the present invention is indicated by the claims rather than the above description of embodiments, and all modifications within the meaning and scope equivalent to the claims are included.

[0057] For example, in the embodiment described above, normal printing and additional printing operations are performed based on image data stored in RAM94. Here, the entire image data may be stored in RAM94 first, and then each printing operation may be performed, or the image data may be transmitted in parts from an external PC, and the printing operations may be performed sequentially from the received parts of the image data until all the image data is received. In the latter case, for additional printing operations, the image data should be transmitted in the reverse order of the order in which it is transmitted from the PC, etc., during normal printing operations.

[0058] Furthermore, in the flowchart of Figure 7 in the above-described embodiment, when the normal printing operation is interrupted, the roll paper Rp is cut and then ejected before the additional printing operation begins. In contrast, after the normal printing operation is interrupted, the roll paper Rp may not be cut, and image formation by the additional printing operation may begin in a region continuous with the region on the roll paper Rp where an image was formed by the normal printing operation. Thus, after the normal printing operation is interrupted, regardless of whether the paper P is cut or not, image formation by the additional printing operation may be performed in a region different from the region where an image was formed by the normal printing operation.

[0059] Furthermore, in the above-described embodiment, a touch panel display 95 is used as a device capable of user input. However, instead of this, or in addition to this, an input unit having physical buttons or switches (corresponding to the "user input unit" of the present invention) may be used.

[0060] Furthermore, in the above-described embodiment, Figure 6 is used as an example of a screen that displays the image formation status during the additional printing operation. However, a screen other than Figure 6 may be used. For example, a screen indicating the image formation status may be displayed on the touch panel display 95 in a manner in which only the areas where the image has been formed are displayed, and areas where the image has not yet been formed are not displayed at all.

[0061] In addition, although the embodiments described above describe the application of the present invention to a printer 100, the invention is not limited thereto. The present invention may also be applied to other inkjet-type image forming apparatuses that eject ink from a head, such as multifunction printers and copiers. Furthermore, it may be applied to laser-type image forming apparatuses that perform image recording processing by attaching toner to the paper P instead of attaching ink to the paper P using an inkjet method. [Explanation of symbols]

[0062] 2. Conveying mechanism 4 carriages 5 heads 6 Moving mechanism 8. Cartridge mounting section 9. Control Unit 10 Ink Cartridges 95 Touch panel display 100 printers P paper Rp roll paper Kp cut paper

Claims

1. A media storage section for containing a sheet-like medium, A media transport unit that transports the sheet-like media from the media storage unit along a predetermined transport direction, An image forming unit that forms an image on a sheet-like medium transported by the aforementioned medium transport unit, A user input section that accepts user input, It is equipped with a control unit, The control unit, A first control that causes the image forming unit and the media transport unit to perform a first operation in which an image indicated by image data received from an external source is formed on a sheet-like medium from one end to the other in the vertical direction of the image corresponding to the predetermined transport direction, An image forming apparatus characterized by performing a second control, in which, if the first operation is interrupted, the image forming unit and the media transport unit are instructed to perform a second operation, which involves forming an image indicated by the image data in a region of a sheet-like medium different from the region in which the image was formed in the first operation before the interruption, from the other end toward the one end, until the timing indicated by the user input received by the user input unit.

2. It has a display, The image forming apparatus according to claim 1, characterized in that the control unit, in the second control, causes the display to show the range of an image formed on the sheet-like medium by the second operation, and updates the content of the display in accordance with the progress of image formation by the second operation.

3. It is equipped with a cutting section for cutting sheet-like media, The image forming apparatus according to claim 1 or 2, characterized in that the control unit causes the sheet-like medium to be cut by the cutting unit after the first operation is interrupted and before the second operation is started.

4. It is equipped with a cutting section for cutting sheet-like media, The image forming apparatus according to claim 1 or 2, characterized in that the control unit causes the sheet-like medium to be cut by the cutting unit after the second operation is completed.

5. The control unit, The image forming apparatus according to claim 1 or 2, characterized in that the media transport unit is controlled such that the speed at which the sheet-like medium is transported in the second operation is less than the speed at which the sheet-like medium is transported in the first operation.

6. The control unit, The image forming apparatus according to claim 1 or 2, characterized in that, in the second operation, the image forming unit and the media transport unit are controlled to complete the second operation in accordance with the timing when the user input unit receives user input, while continuously continuing the formation of an image on a sheet-like medium and the transport of the sheet-like medium.

7. The control unit, The image forming apparatus according to claim 1 or 2, characterized in that, in the second operation, image formation on a sheet-like medium and transport of the sheet-like medium are performed intermittently, and the image forming unit and the medium transport unit are controlled to complete the second operation in accordance with user input received by the user input unit during the period when image formation on the sheet-like medium and transport of the sheet-like medium are stopped.

8. The image forming unit forms an image on the sheet-like medium while reciprocating along the sheet-like medium in a direction perpendicular to the predetermined transport direction in each of the first and second operations. The control unit, The image forming apparatus according to claim 7, characterized in that, in the second operation, the image forming unit is made to perform the reciprocating movement once or more times while image forming on the sheet-like medium and conveying the sheet-like medium are performed, and then the operation is stopped, and this is repeated, thereby intermittently performing image forming on the sheet-like medium and conveying the sheet-like medium.

Images